Abstract

The peel of citrus fruits contains a large percentage of pectin which can be a good substrate for pectinolytic microorganisms. These microbes secrete large amount of extracellular enzymes to degrade the cell wall of substrates. The current study was conducted for the production and characterization of pectin lyase from Aspergillus nigerusing citrus fruits peel as a substrate. The optimum pectin lyase production was analyzed from pectin lyase activity assay. A. niger showed maximum production after 96 h at 30°C, 8.0 pH, 4 mL inoculums and 0.1% peptone. Tween-80 was used as a surfactant and showed negative effect on pectin lyase production. Pectin lyase was purified by the addition of 60% of ammonium sulfate and showed maximum activity at 30°C and 8.0 pH.

Key words: Citrus fruits, pectin lyase, A. niger, peptone.